Method of die rolling



UNITED S WILLIAM P.- WITHEROW, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WITHEROW STEEL COMPANY, OF NEVILLE ISLAND, PENNSYLVANIA, .A

PENNSYLVANIA.

No Drawing.

T 0 all whom z'tmay concern:

Be \it known that I, WILLIAM P. WITH- ERoW, a'citizen of the United States, residing at Pittsburgh, county of Allegheny, and

State of Pennsylvania, haveinvented a newand useful Improvement in Methods of Die Rolling, of which the'following is a full, clear, and exact description. p

The present invention relates broadly to metal Working, an more particularly to die-rolling methods in which accuracy and r broadly, in which variations in dimensions p consisting 1n passing a metal leader through uniformity in the dimensions of the dierolled products are important.

At the present time considerable difliculty is encountered in the art to which this invention relates, in that successive articles produced, .either from the same or' different mills, do not have accurate and uniform dimensions. Many" attempts have been made to satisfactorily produce blanks for certain purposes by die-rolling, due to the enormous output possible in this manner, but variations in the dimensions have made many of these attempts very unsatisfactory.

In my Letters Patent No. 1,502,705 of July 29, 1924, there is disclosed a method of die-rolling in which the temperature of a blank is increased or decreased to decrease or increase respectiye-ly the length of the rolled blank. The variation in the temperature of the blank being rolled is preferably in ac-' cordance with the percentage of reduction to be effected by the die-rolls.

In studying thev art of die-rolling, I am led to the belief that variations in length may be attributed to a considerable extent to the action of the rolls on the metal. amount of work performed on any given length is varied by varying the amount of roll slip, there is a corresponding variation in the length of the resulting article. This -is somewhat contrary to the metal rolling art If the CORPORATION 01:

METHOD OE DIE ROLLING.

Application filed August 1, 1923. swarm; 655,060.

This result corresponds in general to the result obtained by increasing the temperature. On the other hand, if the speed of the rolls is decreased, the effective grip on the metal is apparently increased, thereby subjecting the metal to an increased rolling action which effects a greater flow of metal and consequently a longer blank. This result is similar to the result obtained by decreasing the temperature of the blank. It may be, however, that the results obtained are due to other causes.

In accordance with the present invention, the lengths of the articles may be varied either by a change in the roll speed alone or is desired, the speed of the rolls may be increased to alone accomplish the desired result, or the speed of the rolls may be increased -a lesser amount and the temperature of the metal increased the required amount, whereby the same result isv obtained.

These variations in roll speed and temperature should also bear a different relation to the reduction which is being effected in the metal by the die rolls. In other words, as the percent of reduction increases an increase in roll speed, either with or without an increase in temperature will produce a shorter blank than will be produced at the same temperature if the percent of reduction is decreased.

The advantages of the present invention arise from the method herein described of insuring uniform results 'easily and quickly by merely yaryi'ng the speed of the rolls or eflec'ting a joint variation in the roll speed and the temperature of the metal being 0perated upon by the rolls.

I claim: 1; In the method of die rolling, the'steps a given speed and thereafter passing successive leaders through the same die roll pass with the rolls thereof driven at lower speed if longer blanks are desired than those produced from the first mentioned leader.

8. In the method of die rolling, the steps consisting in passing a metal leader through a die roll pass with the rolls thereof driven at a given speed and thereafter passing successive leaders through the same die roll pass with the rolls thereof driven at increased speed if shorter blanks are desired than those produced from the first mentioned leader,

the increase inspeed being in accordance with the percentage of reduction to be effected by the die rolls.

4. In the method of die rolling, the steps consisting in passing a metal leader through a die roll pass with the rolls thereof driven at a given speed and thereafter passing successive leaders through the same die roll pass with the rolls thereof driven at reduced speed if longer blanks are desired than those produced from the first mentioned leader, the decrease in speed being in ac cordance with the percentage of reduction to be accomplished by the die rolls.

5. In the method of die rolling, the steps consisting in passing a metal leader through a die roll pass with the rolls thereof driven at a given speed, whereby a sample article of a certain length is produced, and varying the length of the die rolled article from the length of such sample by varying the speed of the die rolls.

6. In the method of die rolling, the steps consisting in passing a metal leader through a die rollpass with the rolls thereof driven at a given speed, whereby a sample article of a certain length'is produced, and varying fected thereby.

7 In the method of die rolling, the steps consisting in passing a heated metal leader through a die roll pass with the rolls thereof driven at a given speed and with the leader at a given temperature, whereby a sample article of a certain length is produced, and varying the length of the die rolled article from such sample by varying the temperature of the metal leader and also varying the roll speed of the die rolls.

8. In the method of die rolling, the steps consisting in passing a heated metal leader through a die roll pass with the rolls thereof driven at a given speed and with the leader at a given temperature, whereby a sample article of a certain length is produced, and thereafter passing successive leaders through the same die roll pass, the leaders being at a different temperature than the sample leader and the rolls being driven at a speed different than that used in the rolling of the sample whereby articles differing in length from the sample are produced, both of said variations being in accordance with the percentage of reduction to be effected by the die rolls.

In testimony whereof I have hereunto set my hand.

WILLIAM P. \VITHEROW. 

